Pasteurizer



1 lull WHNHHHHPL In Vania]:

MJJW

' warme yso 1 I April 927 1'. w. w. FORREST PASTEURIZER Filed Nov. 22,

Patented Apr. 19, 1927.

UNITED STATES PATENT ()FFICE.

THOMAS W. W. FORREST, OF OAKLAND, CALIFORNIA, ASSIGNOIR T SUN-MAID BASIN GROWERS OF CALIFORNIA, 0F FRESNO, CALIFORNIA, A COOFERATIVE ASSOCIA- TION OF CALIFORNIA.

rasrnonrznn.

Application filed November 22, 1924. Serial No. {51,568.

My invention has for its object means and filed under Serial Number 1951.-'

I am well aware that food products have heretofore been Pasteurized by hot water, also by steam and third by a combination of steam and hot water, all of which methods are open to numerous object-ions.

In the Pasieurizing of raisins the common methods heretofore practiced have produced wet and soggy raisins which stick together in masses necessitating subsequent handling and treatment before they are suitable for packing. Theraisins during the treatment absorb and hold the heat and also absorb an excess of moisture, frequently resulting in the formation and running of syrup which ruins the packages. Moreover the methods heretofore employed have resulted in the heating of the raisins as a whole, that is the interior of the raisin is raised above left) F. resulting in a destruction of some of the most desirable sugar content or its transformation into caramel, and therefore also a loss of somcof the raisin flavor. The excess of moisture also carries off a considerable percentage of the sugar, reducing the flavor, changing the color and food value.

All of these objections are overcome to a greater or less degree by employing my Pasteurizer and method of treatment which consists primarily of heating the raisins with super-heated steam for a period of a few seconds only and I have found from practice twenty to thirty seconds to be ample.

The application of the higher heat for the shorter space of time than heretofore causes the skin of the raisin to reach a relatively high temperature without any considerable increase of temperature in the interior of the raisins and without introducing within the.

raisin any excess of moisture.

In other words, the skin is thoroughly Pasteurized and conditioned before the interior of the raisin has been raised to a sufficient degree to cause any I destruction of sugar or other deterioration and the heat application is then stopped, resulting in a softened skin and a sufiicient swelling of the cellular tissues and a hydrolyzation of some of the cellulose.'

lhis softening of the skin with the resul"- ing mild inside temperature allows a proper removal of the seeds. The treatment is suiticiently rapid to prevent excessive moisture or the washing a 'ay of the sugar. The seeded raisins are dried and thereafter flow freely and there is no massing or stickiness in the final product.

The full food value of the raisins and their natural color are retained.

By referring to the accompanyingdrawings my invention will be made clear.

, Fig. 1 is a longitudinal view of an apparatus employing my invention.

Fig. 2 'isa cross section of Fig. 1. on the line IIII thereof.

3 is an end view of the discharge end of the apparatus of Fig. 1. a I

Tilhroughout the figures similar numerals refer to identical parts.

A main casing is indicated by the numeral 1 which is preferably of tubular form and has concentrically mounted therein an inner casing 2 perforated in its'upper half substantially throughout its length. Mounted within the inner casing 2 is the spiral conveyor 3 carried on the shaft 1 adapted to be driven by the pulley 5 from any source of power. Synchronously therewith the chain drive 6 operates the inlet rotary valve7 and the chain drives 8, and 9 operate the dis" charge primary valve 10 and secondary valve 11 respectively. The space between the valves 10 and 11 is exhausted by any conventional means through the exhaust pipe 12, and super-heated steam is admitted through the pipes 13, 1 1 and 15 from the main steam supply pipe 16 passing freely into the upper portion 17 of the compartment 21 formed between 1 and 2.

At 30, 31, 32 are water connections whereby moisture may be added to the inflowing steam to suit the requirements of any special treatment and at all times under the control of the operator.

The superheated steam passing through the numerous perforations in the upper part of the inner casing 2 comes in contact with the raisins during their passage under the action of the conveyer 3 from the supply inlet as'indicated by the arrow 18. The raisins during their treatment are caused to ltl 13:1?58 through the inner compartment and are discharged into the raising it) of the valve ltl. Due to the euper-lwated condition of the st ain under which the 'aieins: are Pasteurized during; their transit and through the inner casing: ii there wouli he a discharge of Stlit'l steam were it not" for the secondary discharge valve 11 and a space between the ralrea 1t) and 1.1 which is lzept exhausted through the conventional connections at 12.

r nitahlc lileedera or drains are provided at: 33;), ll. -lin for controlling the steam and water discharge from theconugartmeiit ill and to enahle the operator to secure the conditions; of heat and moisture tratment best suited in inn case.

it tlti l. hare shown the upper portion oi the inner casing: opposite the steam inlets as not perforated to serve a; a liatlle and prevent any extra intenue action on the raisins when panning thereunder.

l have found that in the lhiateurizinc and conditiening of raisins for .-:eedin;.1' and packing that a treatment with super-heated steam for a period of not to exceed thirty seconds is ample and the apparatu is preferalily timed to transfer the raisins from the inlet to the valre it! within approaiinately twenty seconds.

The raiains upon passing through the ralre it] come into the exhaust compartnient hetween the ralrea ill and "it and the excess steam and moisture is there removed so that the raisins pass out at Qt) in a relatircl dr pulled up conditiiai with the shine; entiiciently heated and moisture. treated to enahle the raisins to he readily seeded.

Referring particularly to Fig. 2, it will ie noted that 1 ha re ehown a water jacket in he compartment ill hetwcen the caningl and 3. which water 'jacliet may he varied hy the operator to suit any given r-ct oi conditions. "this water is the result of coiulensation from the super-heated steam entering: from the pipe lti and in its employment the teinperature of the raieini; within the inner 1: sine 22 ll? nuuleratcd or controlled.

it will now he seen that the shins of the raisins during: their passage and treatmentare subjected to a relatively dry intense heat not less than F. fo' a hrief space of time during which the heat action is not permitted to penetrate beyond the surface layers of the raisin and the center of the raisin at no time to exceed 1 1:5 ll.

1 claim:

1. Dried fruit lasteurizing mechanit-an comprising;' a lmrizontally arranged tnhular outer asing prorided with upper controlled steam supply means and lower controlled dran'lage means, a eylimlrieal inner a ing spaced within the outer -asing and a coi'weyor therein adapted to t 'anst'er material through tiiltl, inner casing. said inner casing being provided with a plu 'ality of perforations on its upper side only open to the space hetwcen the cylinders to allow steam action therethrough from said space on said material and said inner casing provided with an inlet valve to control the fruit to the con \eyor and an outlet therefor and means to u ain the outflow of the fruit therefrom to retain the steam.

Dried fruit Pattenrizinc mechanism comprising an outer horizontally arranged tuhular musing and a spaced inner cylindrical casing, a controlled steam supply means and a controlled d'ainage means to the outer casing, a conveyor in said inner cylindrical. casing for fruit to he Pasteurized, sa d inner casing being perforated in its upper portion only and provided with an inlet 'alre to control and deliver the fruit to the conveyor, a pair of outlet *alves in series and exhausting means interposed between said outlet valves.

:3. In mechaniam as set: forth in claim .l water supply means to said outer casing, and means for controlling the depth of water between the casings.

4:. In mechanisn'i as set forth in claim 2 water supply means to said casing: adapted to mingle the water with steam from said am supply means.

A. structure as specified in claim L in which said eteam supply means comprises a steam nozzle entering through the upper part of said outer casing only and provided with a battle to prevent the steam passine" straight from the nozzle tlu'oug'h the perforations of said eylindri val casing.

'li-IOMASdV. \V. FORREST. 

